PCR analysis of rat RNA from the aorta (b–d), vena cava (e–g), and uterus (h–j) for the expression of coding sequences of the OT gene. Ethidium bromide-stained agarose gel showing the PCR amplification products obtained with OT exon-specific primers using reverse-transcribed mRNA from rat aorta, vena cava, and uterus were used as control organs. a, 123-bp ladder of GIBCO/BRL; b, e, and h, 235-bp OT cDNA products of PCR from primers located on exons 1 and 2; c, f, and i, 414-bp OT cDNA products of PCR from primers located on exons 1 and 3; d, g, and j, 362-bp OT cDNA products of PCR from primers located on exons 2 and 3.